Vulcanization accelerator



Patented Jan. 7, 193 6 UNITED STATES PATENT.OFFICE' 2,027,135 IVULCAN'IZATION ACCELERATOR Wilhelm Lommel, Leverkusen-Wiesdorf, and

Rudolf Schriiter, Leverkusen-I. G. Werk, Germany, assignors to I. G.Farbenindustrle Aktiengesellschaft, Frankfort-on-the-Main, Germany NoDrawing. Application January 4, 1933, Serial No. 650,138. In GermanyJanuary 5, 1932 2Claims'. (Cl. 18-53) not a high molecular aliphaticamine, in admix ture with a high molecular aliphatic amine. when usinghereafter and in the claims the term vulcanization accelerator the sameis'intended to embrace vulcanization accelerators a may be mentionedthat while the latter loompounds, at least partly, possess someaccelerating. power, they are not, however, vulcanization acceleratorsin a technical sense.

The present invention is based upon the discovery that "quite generallyvulcanization accelerators are activated to a far reaching extent by thepresence of the high molecular aliphatic 25 amines without the danger ofprevulcanization occurring. Furthermore, the combined use ofvulcanization accelerators and of the amines in question has theadvantage that in'many cases vulcanizates of improved tensile strengthare oba tained, even in case the totalamount of the accelerator and theamine is smaller .than the amount of the respective accelerator employedin the previously known .vulcanization processes. Furthermore, since theamines in question do 35 not discolor the vulcanizates to anysubstantial degree and do not .lend any unpleasant odor to tionaccelerators are activated by the amines in questions? The best resultsare, however, obtained, when applying accelerators which do not 45possess the character of so-called ultraeaccelerators, such asunsubstituted or substituted mer-' captoarylenethiazoles,thiuram-monoand disuliides, diarylenethiazyldisulfides, etc.

Preferred high molecular aliphatic amines are 50 those possessing astraight or branched aliphatic "t other than high molecular aliphaticamines. It.

chain of more than 9 carbon atoms, such as 2-amino-nonodecane,amino-tridecane, heptadecylamines, n-undecylamine, dodecylamines, etc.

Generally, the amount of the amine to be added maybe less than theamount of the accelerator 5 used. For example, amounts of the aminecorresponding to about 0.05 to 0.5% by weight (calculated on the rubberto be vulcanized) will yield good results in most cases.

The term rubber as used herein is intended to include natural rubber aswell as artificial rubberlike masses obtainable, for example, bypolymerizing butadiene hydrocarbons alone or in admixture with oneanother or with other suitable polymerizable compounds, such as styrene,vinyl naphthalenes, acrylic acid, acrylic acid esters,

' acrylic acid nitriles, unsaturated ketones etc.

The following examples illustrate the invention which is not, however;restricted to the specific materials and proportions recited therein:

Example 1 Parts by weight First latex crepe 100 Zinc oxide 5 Sulfur 3Stearic acid 1 are well mixed with r Y i Parts by weightDibenzothiazyl-disulfide 0.6 and A mixture of Z-amino-nonOdecane andozokerite (60:40) l 0.3 and vulcanized by heating. T

The following values were obtained:--

Heating Tfiluiielggeigth Exteraionln 40 2 atm. (superatm) 20mlnutcs. 220(3+) 823 30 minutes..- 251 817 minutes. 198 753 60 minutes 198 770 3atm. jaugsratm.)

20 mitts--. 2 1?; 45

30 minutes 198 m 0.5 atm. uperatm.)

40 minutes Insufllcieutly vulcanized.

- S means separation of sulfur. i

For comparison we give below the values which are obtainable, whenvulcanizing the above mixture with 1 part by weight oibenzothiazyldisultlde and without the addition of 2-amino- 5 nonodecane:--v

Tensile in Extension Heating M. cm in 1o 2 tin. h.

tomitieififiiiin. n2 gs) use ms 855 m4 151 in 738 m s ass in m 30minutes 186 788 0.6 atm. (superatmosph) 40 minutes Insuflieientlyvulcanized.

( 8 means separation of sulfur.

Example 2 Parts by weight 25 Raw rubber 100 Sulfur 3 Zinc oxide 5Stearic ari 2 Mercaptobenzothiazole 0.4 30 Z-amino-tridecane 0.1

are well mixed and vulcanized by heating.

The following values were obtained:-

Extensi n Heating 110 0. a n; in

208 795 220 m 220 set 190 115 195 805 The following values were obtainedwhen vulcanizing the above mixture, but without the addition of2-amino-tridecane:

XE means separation of sulfur. 5 az oggilth the addition of 0.4 part byweight mercapto-benzm Bfligith the addition oi 1.0 part by weight 0!mercapto-benzo- Example 3 A mixture of 70 Parts by weight Raw rubber 100Sulfur 3 Zinc oxide Dibenzothiazyl disulflde 0.8

15 2-amino-nonodecane 0.2

obtained in the usual manner, is vulcanized by heating.

The following values were obtained compared with those obtained byvulcanizing the above mixture, but without the addition of2-amino-nonodecane:--

Without addition With addition Heating 110 0. Tensile Tensile strengthExtension strength Extension s-l qsJ qiiilminutes Insufli-Insufliciently ciently vulcanvulcanized. 3 atm. (superatm) ml 155 so 905242 w 20 min 115 865 ms 806 30minutes.. 183 ass an ass (+)S meansseparation oi suliur.

The above table shows the considerable increase of the tensile strengthby the addition of the small amount oi Z-amino-nonodecane. The modulusshows that the vulcanizates obtained with the addition of the2-amino-nonodecane are essentially tighter.

Example 4 A vulcanization mixture of Parts by weight Raw rubber 100Sulfur 2.5 Zinc oxide 5 Tetramethylthiuram disulfide 0.252-amino-nonodecane 0.1

yields, when vulcanized for 20 minutes at 1.5 atmospheres(superatmospheric pressure), a vulcanizate of a tensile strength of 112kg./sq. cm. at an extension of 700%. When working without the addition,a vulcanizate of a tensile strength of 94 kg./sq. cm. is obtained; fromwhich it results that also in this case a tighter vulcanizate with astronger nerve is obtained.

Example 5 A mixture or Parts by weight Raw rubber 100 Zinc white 5Sulfur 3 Dibenzothiazyl dlsulflde 0.8

Example 6 When vulcanizing the mixture of example 5 with 2.5 parts byweight of sulfur and 0.25 part by weight of tetramethylthiuram disulfldeand with the addition of (a) n-undecylamine (b) ndodecylamine (c)n-heptadecylamine the following values were obtained for the tensilestrength in kg./sg. cm. at an extension of 700%. which show that thevulcanizates obtained with the addition of the above named amines areconsiderably tighter than those. obtained without such an Idditionz- I40.: +0-1pu-t +0.1

1! 0s w: a

m byagl i t by a ight by t wmlnntes. Inmfllcientlyvnleanized m l utel asas u so mmlnutq. 81 111 118 111 39minntel....... so ms in m.

intheaboveexamplesthehizlimolecnlnraiiphatic amines may be appliedineoniimction with. oaokerite, paraflln, parafln oil or other similaragents.

We china- 1. The process which comprises incorporating a with rubbersulfur, a vulcanization accelerator other than an aliphatic amine and aprimary aliphatic amine possessing a straight or branched aliphaticchain of more than 9 carbon atoms.

2. The vulcanizates obtainable according to 10 the process as claimed inciaim 1.

mm mom scnadm

